Windshield wiper



y 16 1929; I v K. KNUDSEN I 1,720,906

WI'NDSHIELD WIPER .Filed. Ma 27, 1926 2 Sheets-Shet 1 I Patented July 16, 1929.

UNITED STATES NT g it: .I xnnsmnmnsnn, or CHICAGO, ILLINOIS,- AssIGiroBjro sm .conronamon, A oomonnrron or nnmpm s .wmnsnmnn mm Application filed May 27, 1926. serial m5. 1i

My invention relates to electric wind shield wipers particularly to that type in i which an electric motor produces the riving power. The important object of the invention is to translate the circular uniform movement of a crank pin driven by the motor into oscillatory swing of the wiper bar at practically uniform speed and torque and with uniform load on the motor. The invention also involves other features of construction, arrangement and operation all of which are fully disclosed in the following specification in connection with the drawlngsfonj which drawings:

Figure 1 is a plan view, with parts in section, showing a wiper structure applied to a Wind shield;

Figure 2 is a front elevational view with the enclosure covers removed and with the left end of the structure in vertical diametral section; v

Fi re 3 is a front elevational view of the gear ousing with the cover removed;

' Figure 4 1s a sectional view on plane 4-4 Fig. 2.

Briefly describing the wiper structureto which I have shown my invention applied,

.the housing structure for the wiper. operating parts comprises the main section .1 which is cylindrical and has the radial rectangularextension 2 which together with the main section forms an enclosure and support for the field frame or element 3 of the electric propulsion motor. The extension 2 has the detachable cap or cover 4 held in place by screws 5.

The main section 1 of the housing has also the extension 6 forming an enclosurefor the gearing and translating linkage between the electric motor and wiper arm, the housing structure fi'having the detachable cover 7.

The housing structure comprises further the end cap 8 cover 9. A

Extending rearwardly from the main housin part 1- and the gear housingsection and a switch lever supporting are t e lugs IO-and 11, respectively, for seatin 'the structure against the frame 12 of ,fl-fwin shield glass 13. The lug 10 has the 6o"- threaded post *14Z'extendingtherefrom and which engages through the opening 15 through t e wind shield frame, rubber or other resilient washers 16 and 17 being infterfiosed between the wind shield frame and.

v25. between the min a 1,720,906 ,QOFFICE.

terminating within th'gear hbusihg ti while the rear end of the tube is threaded and pro jects through the "hole. 20 through 'thefwi'nd shield frame to beengag'ed 'fby a nut '21."

Rubber or other resilientwa sh'ers 22"andl23;

are interposed to eng e".

frame.

Describing 3 i i".thi is 2tf$ rui ture, the armature "shaft :21 extends axiauyr through the .main liousingf'li fAtfit'sj right end the shaftis-jou'rna' housing 6, the shaft at itsextend ing intothe end cap Swheref'it-hasj side bean.

ing in the bushin .'26"andl"thr1ist bearing.

against the ball 2 'rhejfielas fisme 3 is" constructed of laminations 1 3", tl 1e inner faces of the poles receiving between them respectively.

The outer surfaces of the field poles are' concentric with the housing sectionjl, the field frame having its axial displacement limited by theribs 35 andBG'F'fOrmed'in the 2. The field frame has and 38"a distan'ce below extension housin the side ledges? the outer edge of the housingf2;' andfseated on said ledges and between the; abutment ribs 35 and 36 are the arcuatepspr-ings 39of arranged -with their contact'sides smear be. abutted against by the cover 4'when'1tf is secured to the housing part22by the screws 5, the pressure of the cover. against th e springs causing the ends of the jto press against the end edges of'theledges 37 and one-or more la ers, the springs being1 38- so that thesspringsfWi'1l' tend tokeep the I I field frame anchoredimidwaybetween the abutment ribs 35 and'36 ,f as' "shoWn-;in Figure 1. The field frame' will thus base-- curely held .in proper position -within" the housing structure to cooperate-properly with the armature; The commutatorffl mounted on the armature shaft is enga 'e'd b "the brushes 43 and 44 mountedfon su table rush holders 45 and 46. t 1

-Theright end of the armature shaft 24 extends into the 'gear housing cut i to form a gear worm 83 which meshes with -b meansof a nut 86. The armature sha t 96 so that the wiper mechanism will :fierating receives the crank pin .90. A.

a uts against an L bracket 87 adjustably secured by means of a screw 88 which is shdable in the slot 89 formed in the bottom wall of the gear housing. By adjusting this abutment bracket against the right end of the armature shaft, the left end of the shaft will be kept in proper engagement with the thrust bearing ball 27 and the desired and play of the shaft can be readily adjusted Theworm gear 84 is below the worm 83 and has a crank pin 90 extending therefrom.

Above the worm 83 is the bushing 19 hereinbefore referred to, this bushing forming a bearing for the operatin rod 91 which, at its outer end, has secure thereto the wiper arm supporting fitting 92 and which, at its inner end, is bent to form a lever 93 terminating in a knob 94 by means of which the rod 91 may be readily oscillated manually to swing the wiper arm back and forth.

Seating against the inner end of the lug 11 and receiving the rod 91 is a sleeve or hub 95 to which is secured the crank arm 96, this crank arm being connected with the crank in 90 through a cam link 105 to be presen 1y. described. In the end of the sleeve 95 are the notches 97 for receiving a pm 98 on the rod 91, the engagement of the pin in the notches causing the rod to be secured to the sleeve and to the cranlgearm operated by the. motor. A U-shaped spring;99 receives the outer end of the rod and abuts against the end'of the bushin 19 and a cotter pin 100 extending throng the rod, th tendency of the spring being .to pull the rod to hold its, pin withm the slot 97 and to thus couple the rod for power drive by the motor. Upon an outward pull on the rod a suflicient distance to release the pin from the slot the rod can be turned manually to operate the wiper independently of the motor. a

The cover 7 for the gear case or housing 6 has a'bearing lug 101 for receiving) the hub 95 of the crank arm 96, the lug eing filled with packing material 102 such as felt in 'orderto prevent leakage of lubricating material put into the gear housing for the arts therein. A' gasket 103 is o provi ed for the cover 7 to serve as a seal against escape of lubricant.

The cam link 105 is in the form of an L shaped metal plate, its vertical arm being pivoted at its end by pin 106' to the end of the crank arm 96, while in the horizontal arm of the link is the cam slot 107 which guide link 108 is pivoted at itsouter end to the corner of the cam link and at its inner end is pivoted on a post 109 by the ipin 110. This link guides the vertical bod cam link. A retainer p ate 111 is secured on 0st 112 bya screw 113. The upper end of t 118 plate overlies the crank arm 96 and holds it in proper position on the rod 91.

movement of the The lower end of the retainer plate enga es against the conical end of the pivot pin 10 and holds this pin with its head against the ordinary straight link the uniform rotary motion of the crank wheel 84 would be translated into harmonic oscillatory" movement of the crank arm 96 and the rod 91. The purpose, however, is to have the wiper arm swing with uniform motion suflicientl retarded or rounded off at the ends oi the strokes to prevent abrupt reversals, and this' is accomplished by the cam link 105 which, by means of the crank pin and the guide link 108, is moved bodily and which also has rotational movement on its pivot connection with the guide link. The cam slot 107 is formed to produce the desired proportional rotation and bodily movement of the cam link 105. The slot is of a width to permit eas travel therethrou h of the crank pin an for engagement of the crank pin with either the upper or lower surfaces of the slot. The slot shown has the slightl upwardly inclined longer section 114 and he slightly upwardly inclined shorter section 115,-the surfaces at the juncture of these sections being slightly rounded to permit easy travel therethrough of the crank pin.

In Figure 2 the crank arm 96 is shown "at the lower end of its swing, the -crank wheel 81 rotating in clockwise direction. The crank pin has just'finished its travel through the section 115 of the cam slot and is about to engage with the upper surface. 116 of the slot section 114. During such engagementthe cam link will be rotated in counterclockwise direction to start the crank arm 96 on its u ward swing with uniform motion, the rotation of the cam link being gradually 'reduced and the bodily movement being gradually increased as the crank pin. radius comes into coincidence with the radial line of the guide link 108. During such travel of the guide link and crank p n through the horizontal radial line the movement of the cam link is practically all bodily, the proportion between bodily'and rotational movement be ing, as before explained, such that the crank arm 96 will be given a uniform motion.

Now,'as the crank pin travels toward the upperpart of its orbit the bodily movement of the cam link gradually decreases and rotational movement in clockwise" direction increases as the crank .pin engages against the 114; sii ch' ib'tationa'l f inovement" increasing sufficiently rap1dly =te cause the crank armlower siffrfaca i li of the cam slot section 96 to continuehifnwni'fo'i'M motion, and the crank' 'ann finally i'eachesf the; upper end of its swin'gg-asyshowm in Figure 3. The crank w; arm sge eaga es wifli ni ate-118 and then fora rt"the-crank=pintravels idly th nifs'lofifinii gradually re-"engages 1o -with 'the' ea -surface 11-7--and tends to can as swing the linkblockwiselbm such rotaav v 'td-{by-the -stop 118 and thereres'sure offtl ifcrank pin against A-sltlie crank pin is 'a ;from"*the' pivot conc'onsideiablel distance nectidn of fthe fc'ain' liiik with the guide link IDS-the ldowiiward bodily movement of the cam link ware-e of such rate as will give to the crank arm 96' the desired uniform motioni As the crank pin 'Iiow" approaches its horizontal'radiu's'of revolution, itwill enter the ar -sta ns na ve-a s; inclination will balance the o'therwise" accelerated movement of the cam f liiil'r' and the uniform motion of the crankai'iii 9( i' -wifllbejmaintained. During travel'of'the' crank pin through the horizontal rad ant, revolutionith'e'bodily movem t, of th ca'u li s; ually decreasea andfas thecrank pin reaches the lower se-ction' of its revdlution it engages with the inclined lower surface 119 of the slot section"" 1 15',iand rotaryijmotion 'ofthe cam link' will "accelerate to compensate for the retarding bodily-movement and the uniforig'motion'of the crank'arm 96 is main tain . The crank arm 96 yvill now be at the lower end of its swingmg movement as shown" in Figure 2, and while the crank-pin is traveling through the juncture of the cam slot sections and just before it engages with the upper surface 116, the movement of. the cam. link is yery slow, but it becomes nor.- mal as the crank pin engages with the surface. 116 to. start the upwardflswingof the crank aarm. Thus, .by the interposition of the cam link with its cam slot, and the guide linkwhich guidesthe bodilyand rotational movement of the cam link, the uniform circular travel of the crank pin -is translated into swing of thecrank arm; 96 [and wiper arm with uniform.mo'tion and with gradual but comparatively prompt rev'er-' sals at the strok ends; -The wiper arm is 7 wiper blade 126.

In the arrangement shownithe wiper arm issecured to eXtend from the driving rod 9 at rightangles; to the crank arm 96 and 1 use" the linksto move predominates but grad- 1' cam slot in its base for r is wiped back and forth across the face of the wind shield with uniform motion' and torque when the" motor is'connected with the' driving rod. The motor will be in driving connection with the wiper arm when the driving rod pin 98 is in' the slot 97 of the crank arm hub 95, the spring 99 tending to maintain such engagement. At times it may be desirable or necessary to operate the wipermanually and for purpose the; emergency crank 93 is provided on the drivin red 91. EB first pulling on the crank su ciently to isconnect the pin 98 from the slot 97, the rod can then be readily. turned by means of the crank and the wiper arm-swung manually. Then when it ,-is released and the pin brought back into the slot the motor will be connected to drive the wiper mechanism. Release of the pin from 'the slot will permit theldriving rod to be operated entirely independently of the crank -rm.'96 and the linkage and driving parts within the gear case' 6.

Having thus described claim as follows: 1

1. The combination of a driving motor, a crank wheel having a crank pin, said motorl my invention, I

being'connectedto rotate 831d crank wheel to give said crank pin uniform motion through a circular ath, a driving shaft, a crank arm'on said riving shaft, a connecting cam link connected with said crank arm and having extended cam engagement with said crank pin, andguide means eooperating with said cam link to translate the uniform circular travellof said crankrpin into swinging movement of said crank arm with substantially uniform motion.

2.; The combination'of a crank Wheel hav- --in'g a crank pin, means for driving said crank wheel at uniform rate whereby said through a'circular orbit a driving shaft, a crank arm on said she a cam link connected to-the end ofsaid crank arm, said link at its other; end having a cam .slot re-. ceiving said crank pin, andvmeans for. iding the 'bodil moveinentof said cam ink,

crank pin will travel' with uniform speed s'a1d cam lin andguiding means causing 4 therevolving movement of said crank pin to be translated into swingingmovement of said crank arm, at substantially uniform p -4 I 3. The combination of a driving shaft, a crank arm on said shaft,'a'crank wheel having a crank'pin, means for-driving said crank wheel-at uniformspeed whereby, said.

ment through a circular -path at uniformspeed, an la-shaped cam link pivoted at its upper end to said crank arm and having a iving the crank pin, a guide member for iding the bodily crank pinflwill be-given a revolving move movement of said cam linkg-said guiding member -and.link cooperating to translate connect ng the revolving travel of said crank pin into swinging movement of said crank arm at substantially uniform 4. The combination 0 'a crank wheel having a crank pin, means for rotating said crank wheel at uniform speed to give said crank pin a circular orbit of travel, an o 'r'- ating shaft, a crank arm on said shaft a connecting link supported for bodily and rotational movement, one end of said link bellzfi connected with said crank arm and its .0 er. end having camming cooperation with said crank pin, said connecting link translating the uniform travel of said crank pin into swing of said crank arm and driving shaft at uniform I 5. The combination of a crank wheel having a crank pin, means for'rotating said crank wheel at uniform speed to give said! crank pin a circular orbit of travel, an opcrating shaft, a crank arm on said shaft, a a. guide link pivoted to said connect link intermediate its ends, one end of sald connecting link being connected with said crank arm, the other end of said' connecting link having acam slot said cam pm, said pin and-cam slot connection causing the rotary travel of said crank pin'to be translated into swing of said crank arm at substantially 'umform speed-throughout the major'portion of its stroke and .re-

. crank wheel at uniform.

ta'r'ded movement at the ends of the strokes abrupt reversals. ination of a crank wheel havmeans for rota sai for preven 6. The com inga crank pin,

shaft, a crank arm on said aft, a connecttermediate its ends for guiding ing link connected at one end with said crank arm and having cam surfaces at its other end, said crank pincooperating with said cam surfaces to cause bodily and rotational movement of said conneetmg link, and a pivot support for the rotational movement of said connecting link adap bodily movement of said-link, the combined bodily and rotational movement of said connecting link translating the revolution of said crank pin into oscillation of said crank arm at substantially uniform speed.

'1. The combination of a crank wheel having a crank pin, means for rotating said crank wheel at uniform speed, an operating shaft a crank arm on said shaft, a connecting connected at one end with said crank arm, the other end of-said connecting link having a cam slot extending transversely relative to a line connecting the axes of said crank wheel and crank arm,- said crank pin enga in said cam slot and co- 0 ting therewit to cause bodily and ro-' tational movement of said connecting link, a pivot support for said connecting link inthe rotational movement thereof, said ivot support being shiftable to follow'the movement of said link, the combined bodi and l rotational movement of saidlink transhlting 1 the revolution of said crank pin into swing of said crank arm at substantially uniform speed. V In witness whereof, I hereunto subscribe d my name'this'24th day of May, 1926. a 'ving v KARs'rEN KNUDSEN.

ted to follow the 

